Prof. Judith Curry has been the subject of a large degree of blogospheric talk recently. She has her own site here where the last week or so has seen considerable discussion of the ‘IPCC dogma’ or ideology. I would recommend people who haven’t followed to read essentially all of her posts in November to follow this since I’m not going to give a detailed summary here. Curry’s posts have essentially boiled down to the fact that the IPCC “insiders” have acted as dogmatic or as ideologues.
Unfortunately, Judith’s definitions (and the array of comments) of what this looks like are so broad that signing petitions on climate change, a professional society agreeing with the IPCC, or educating people who don’t have an opinion qualifies to make the “IPCC side” a dogma. The notion is that the “insiders” (whatever this means) have a case of the absence of doubt, intolerance of debate, appeal to authority, a desire to convince others of the ideological “truth”, or a willingness to punish those that don’t concur. The hundreds of comments generated in the discussion at her site by now have ranged from various degrees of extremes on what exactly qualifies under the definition of ideology. My aim with this post is only to offer some incomplete thoughts and a groundwork for which discussion can proceed, since much of the discrepancies in views come from varying premises rather than different conclusions.
I think there’s a lot of misconception on this issue and I see no evidence that Judith is thinking clearly with respect to her claims about the IPCC. Much of the debate has centered around semantics and definitions, so I want to start off with what many people take as “sides” to the debate, particularly when saying things like “the IPCC view” or identifying what a “skeptic” means. Much of the confusion is centered directly on how the scientific community comes to acquire knowledge on a specific topic, or how knowledge of global climate change has evolved.
The fourth assessment report of the IPCC consisted of three volumes of work, on the scale of ~1000 pages each, with the goal of summarizing research in the areas of the physical science, impacts, and policy of climate change. The AR4 does not represent original research, and so to begin with what Judith and other commenter’s refer to as the “IPCC view” is in reality the aggregate work done by the community in whatever sub-topic is being discussed, expressed as a summary of the “balance of evidence.” This cannot involve a static world view by definition, but will necessarily be modified as the community does more research and new or better understanding arises. If this were not the case, no need for an AR5 would exist. I also say ‘subtopics’ because the IPCC consists of thousands of “claims” ranging across various chapters, and with varying degrees of certainty. The WG1 alone directly involves research from the sea level, glaciology, paleoclimate, radiative transfer, temperature observation, modeling, etc communities and obviously in many cases these people will not interfere with each other. An expert on detection and attribution is probably not going to be talking about observations of sea level rise.
Perhaps we’re made to believe it’s only the central claims that is being argued as dogmatic (such as in the summary for policy makers) or the detection and attribution stuff linking anthropogenic causation to temperature increases, but this never becomes clear. This isn’t just being picky; by ignoring the complexity of what the IPCC discusses and lumping it into a single view, you cause people who aren’t interested in the discussion to look at the IPCC as the “pro-AGW camp,” which then artificially distinguished this from the “skeptics” which we are to presume are the “anti-IPCC” camp. This does an injustice to skepticism, but also to what the IPCC does.
Secondly, a clearer picture needs to be made when we say “AGW theory.” There is no such theory, and the categorization (at least in my experience) allows for a wide degree of interpretations, accusations, and straw man attacks. The label allows for a complete mischaracterization of what the science says, but more importantly it loosely defines to what extent new conclusions (such as lower or higher sensitivity, or higher or lower observed sea ice retreat compared to models) become consistent with “AGW theory.” For example, is a sensitivity of 0.5 degree per 2x CO2 consistent with “the theory?” 3 degrees? 10 degrees? Do more or less hurricanes in the future become (in)compatible with the theory? What about El Nino behavior in the future? Clearly, we don’t want all of these sorts of questions to be subjective interpretations on what constitutes compatibility, or the need to introduce letters such as ‘CAGW’. Once we label it as ‘catastrophic’ we’re less in the domain of physical theory and in the domain of interpretation, or just name-calling and straw man attacks. A basic understanding of the science and the ability to logically collect and interpret information goes a long way here.
A more complete description is that ‘AGW’ is a consequence of various theories in physics. The theories of radiative transfer are relevant not just for warming, but for understanding the atmospheres of stars, for Mars, or interpreting satellite images taken from space. There’s a high degree of thermodynamics and physical principles involved, such as the conservation of energy. CO2 increases involve an absolute necessity to force the outgoing longwave energy escaping Earth to go down for a fixed T. The total energy balance depends on all forcings too, not just CO2, but CO2 is the most readily capable agent to cause large change in the near future. The sun changes only too slow or too small to make much of an impact for the centennial timescales many people are interested in, volcanoes express a significant surface impact only for short times, and other greenhouse gases have been relatively secondary in importance and there’s no reason to suspect that will change. Even to the extent that climate sensitivity is low, CO2 can still triple or quadruple eventually and so it’s tough to see an alternative to not causing a large degree of warming in the future if fossil fuels aren’t cut down.
It is of course a value judgment to determine whether 3 degrees of warming is meaningless to your life. But it should be kept in mind that science is not just an isolated tool to advance knowledge for its own sake and reject bad hypotheses. To some extent a lot of knowledge is purely academic, such as studying what happens in a model when you remove all the CO2 from the air, but science can and should serve as a support for policy. It can and should serve as support for everyday people. Medical research is an obvious example. A petroleum geologist telling you to look for oil here and not over there is not dogma; it’s education and advising. A doctor telling you what a bad vs. a good diet looks like is not him pushing his dogma of health science. Expertise is valuable and it matters, and people treating climate science differently is just absurdly odd. Atmospheric science has become so relevant to people’s lives, and not just climate change, but in conversations of the daily weather. The ozone issue is an example. In the mid-century, nuclear testing was done in the stratosphere with the thought being that the air was so stably stratified and would not readily mix with air lower down, yet science showed that in fact this happened all the time. This can be accomplished easily for example by forming a frontal zone t not at the surface but at the tropopause. This knowledge should be given to policy makers. Of course we can’t tell you that the technique of blowing off bombs in the stratosphere would be morally wrong without getting into some philosophy, but as Raymond Pierrehumbert said in connection with the possibility of a runaway greenhouse happening on Earth, “No doubt Pielke Jr., and maybe Judy Curry, would think I’m making a value judgement [sic] outside my purview as a scientist when I say I think it would be a bad thing for the Earth to turn into Venus, but I’m willing to go out on a limb and say that anyway.”
As for “skepticism,” it’s an unfortunate circumstance that the label has inherently been given a bad name on the blogs. This isn’t because of intolerance toward debate as much as the large number of people who criticize the science, or even declare conspiracies and fraud, with an apparent willingness to mislead or ignorance of the subject. THIS EXISTS. It’s not dogmatic to point that out. It’s not dogmatic to point out that people like Pat Michaels or Tim Ball or Chris Monckton have lied to people, or that institutions exist to undermine credibility with no cares for advancing the science. Thus the term “denier” has formed. What’s more, it’s very easy to separate these type of people from a legitimate scientific skeptic, or a curious student, from the mere structure and flow of the argument upon casual inspection. Skepticism is healthy for science, but in no reasonable context can it be defined as the relentless rejection of any body of evidence that goes against your preconceived notions. To be blunt, while one can certainly see emotionalized references to polar bears drowning, or misattribution of a heat wave to climate change (particularly moreso in the public sector than in the scientific community), the type of behavior of denialism described above is very one-sided in this ‘debate.’ I find no reason not to equate this with creationism, an ideology formed not to advance biological science, but to defend a certain interpretation of a theological viewpoint at all costs.
Some claims, like “the greenhouse effect doesn’t exist” are just pure fantasy. But in general, separating a skeptic from a denialist is not about the claim as much as the process of reaching the conclusion and the willingness to modify that conclusion. Those that argue for a low climate sensitivity are often perceived to be more ‘skeptical’ than ‘denialistic’ for instance, but I don’t think the claim is inherently relevant. Rather, some people have to tap-dance a lot to argue for a low sensitivity, and seem to only cite their work while ignoring a large collection of evidence to the contrary. I don’t see how this is inherently beneficial to scientific progress.
Meanwhile, there are many interesting debates to be had within the scientific community. Climate sensitivity is one of them, but in a much different context than whether it’s “catastrophic” or not. There are many topics to be ‘skeptical’ about, one of which is the degree to which anthropogenic perturbations has or will modify hurricane patterns. It’s important to realize that the structure of this “AGW theory” is not a stack of cards that is one publication away from being broken. There are endless components to what we call ‘climate change.’ On the flipside, it took over half a century to convince the scientific community that changes in CO2 could even be a significant player in climate change, to say nothing of whether humans would or could modify its concentration. Arrhenius is often described as quantifying this first in 1896 but the fact is that he was an outlier for a considerable amount of time.
Finally, we’re going to be endlessly stuck at a cross-roads if discussion is stifled. Judith apparently thinks this is occurring, but a glance into the refereed literature clearly shows this is not the case. This is, whether you like it or not, the avenue by which new ideas need to be forwarded. We’re also going to be stuck at a cross-road if you perceive the progression toward unanimous agreement by the informed as a sign of dogma as opposed to robustness of the conclusion.